Brickwork
Brickwork is masonry produced by a bricklayer, using bricks and mortar to build up brick structures such as walls. Brickwork is also used to finish corners, door and window openings etc. in buildings made of other materials. Where the bricks are to remain fully visible, as opposed to being covered up by plaster or stucco, this is known as face-work or facing brickwork. Brick dimensions Brick sizes are generally coordinated so that two rows of bricks laid alongside, with a mortar joint between them, are the same width as the length of a single brick laid across the two rows. That allows headers, bricks laid at 90 degrees to the direction of the wall, to be built in and tie together two or more layers, or wythes, of brick. The thickness of a brick wall is measured by the length of a brick, so a wall one brick thick will contain two layers of brick, one and a half bricks is three layers etc. A common metric coordinating size is 215 x 102.5 x 65mm, which is intended to work with a 10mm mortar joint: 75mm course height, 215mm wall thickness etc. This is based on the earlier inch sizes. There are many different standard brick sizes worldwide, most with some coordinating principle. Wall thickness and construction Solid brickwork The simplest type of wall is constructed in solid brickwork, normally at least one brick thick, and the different bricklaying patterns are ways of incorporating headers to tie together the layers of brick. Cavity walls In a cavity wall, two layers (or leaves) of brickwork are tied together with metal ties, with a cavity or 2 to 4 inches that may be filled with insulation. Brick facing A non-structural outer facing of brick is tied back to an internal structure: a layer of blockwork, timber or metal studwork etc. Terminology Positions: Stretcher: a brick laid horizontally, flat with the long side of the brick exposed on the outer face of a wall. Header: a brick laid flat with the short end of the brick exposed. Soldier: a brick laid vertically with the narrow ("stretcher") side exposed. Sailor: a brick laid vertically with the broad side exposed. Rowlock: a brick laid on the long, narrow side with the small or "header" side exposed. Shiner: a brick laid on the long narrow side with the broad side exposed http://www.hansonbrick.com/en/architect/positions.php Brick Types. There are two main types of clay bricks: pressed and wire cut. Pressed bricks usually have a deep frog in one bedding surface and a shallow frog in the other. Wire cut bricks usually have 3 or 4 holes through them constituting up to 25% of the total volume of the brick. Some ‘perforated’ bricks have many smaller holes. Brick Usage. There are three main categories of use, and both pressed bricks or wire cut brick types are used in all three categories. Facing brickwork is the visible decorative work. Engineering brickwork, often seen in bridges and large industrial construction but may also be hidden in ground works where maximum durability is required e.g. manhole construction. Common brickwork is not usually seen and is used where engineering qualities are not required; below ground in domestic buildings and internal walls for instance. Frog up/down. A frog is a recessed part of a surface of a brick. Pressed bricks are laid ‘frog up’ when maximum strength is required especially in engineering work. This method also increases the mass of a wall and decreases sound transmittance. Pressed bricks may be laid frog down; this method is favoured by the bricklayer since less mortar is required for bedding. There may also be a marginal increase in thermal insulation due to the entrapped air pockets. A disadvantage of this method is that with bricks having a very deep ‘V’ shaped frog there may be some difficulty in making reliable fixings to the wall when the fixing hits an air pocket. Wire cut bricks may be laid either way up but some types of wire cuts have a textured (combed) face creating folds in the face of the brick which is directional. It is advisable to lay these bricks with the folds hanging downwards to maximise the weathering characteristics of the brick. Ties or cavity ties are used to tie layers of brickwork into one another, to form a structural whole. A common type is a figure-eight of twisted wire, generally stainless steel to avoid failure due to corrosion. The loop at either end is buried in the mortar bed as the wall is built up. Mortar is a mixture of sand, lime and Portland cement, mixed with water to a workable consistency. It is applied with a bricklayer's trowel, and sets solid in a few hours. There are many different mixes and admixtures used to make mortars with different performance characteristics. British bricklaying terms Terms usually known in UK:Brickwork by W.G. Nash. Published in December 1988, Hyperion Books Bat - a cut brick. A quarter bat is one quarter the length of a stretcher. A half bat is one half. Closer - a cut brick used to change the bond at quoins. Commonly a quarter bat. Queens closer - a brick which has been cut over its length and is a stretcher long and a quarter bat deep. Commonly used to bond one brick walls at right angled quoins. Kings closer - a brick which has been cut diagonally over its length to show a half bat at one end and nothing at the other. Snapped Header - a half bat laid to appear as a header. Commonly used to build short radii half brick walls or decorative features. Squint - a brick which is specially made to bond around external quoins of obtuse angles. Typically 60 or 45 degrees. Dog Leg - a brick which is specially made to bond around internal acute angles. Typically 60 or 45 degrees. Corbel - a brick, block or stone which oversails the main wall. Cant - a header which is angled at less than 90 degrees. Plinth - a stretcher which is angled at less than 90 degrees. Voussoir - a supporting brick in an arch, usually shaped to ensure the joints appear even. Creasing tile - a flat clay tile laid as a brick to form decorative features or waterproofing to the top of a garden wall. Cramp - or frame cramp is a tie used to secure a window or door frame. Movement Joint - a straight joint formed in a wall to contain compressible material, in order to prevent cracking as the wall contracts or expands. Air brick - a brick with perforations to allow the passage of air through a wall. Usually used to permit the ventilation of underfloor areas. Pier - a free standing section of masonry such as pillar or panel. Quoin - a corner in masonry. Stopped end - the end of a wall which does not abut any other component. Dog tooth - a course of headers where alternate bricks project from the face. Saw tooth - a course of headers laid at a 45 degree angle to the main face. Sleeper wall - a low wall whose function is to provide support, typically to floor joists. Honeycomb wall - a wall, usually stretcher bond, in which the vertical joints are opened up to the size of a quarter bat to allow air to circulate. Commonly used in sleeper walls. Party Wall - a wall shared by two properties or parties. Shear Wall - a wall designed to give way in the event of structural failure in order to preserve the integrity of the remaining building. Fire Wall - a wall specifically constructed to compartmentalise a building in order to prevent fire spread. Withe - the central wall dividing two shafts. Most commonly to divide flues within a chimney. Toothing - the forming of a temporary stopped end in such a way as to allow the bond to continue at a later date as the work proceeds. Indent - a hole left in a wall in order to accommodate an adjoining wall at a future date. These are often left to permit temporary access to the work area. Tumbling in - bonding a battered buttress or breast into a horizontal wall. Racking back - stepping back the bond as the wall increases in height in order to allow the work to proceed at a future date. Brickwork bonds Image:Flemish bond.svg|Flemish bond Image:Running bond.svg|Stretcher bond Image:English bond.svg|English bond Image:Spanish bond.svg|Header bond Image:Rat-trap bond.svg|Rat-trap bond Image:Herringbone bond.svg|Herringbone bond Image:Basketweave bond.svg|A simple basket bond pattern Flemish bond , Gloucester County, Virginia, one of earliest works in America in Flemish bond. The bricks were imported from England.]] Flemish bond, also known as Dutch bond, has historically always been considered the most decorative bond, and for this reason was used extensively for dwellings until the adoption of the cavity wall. It is created by alternately laying headers and stretchers in a single course. The next course is laid so that a header lies in the middle of the stretcher in the course below. This bond is one brick thick. It is quite difficult to lay Flemish bond properly, since for best effect all the perpendiculars (vertical mortar joints) need to be vertically aligned. If only one face of a Flemish bond wall is exposed, one third of the bricks are not visible, and hence may be of low visual quality. This is a better ratio than for English bond, Flemish bond's main rival for load-bearing walls. A common variation often found in early 18th century buildings is Glazed-headed Flemish Bond, in which the exposed headers are burned until they vitrify with a black glassy surface. Monk bond is a variant of Flemish bond, with two stretchers between the headers in each row, and the headers centred over the join between the two stretchers in the row below. Stretcher bond Stretcher bond is the simplest repeating pattern but it is only suitable for a wall half a brick thick, the thinnest possible wall. Such a thin wall is not stable enough to stand alone, and must be tied to a supporting structure. It is common in modern buildings, particularly as the outer face of a cavity wall, or as the facing to a timber framed structure. American bond By one definition, Common, American or Scottish bond has one row of headers to five of stretchers. The number of strecher courses may vary from that, in practice. For example, the brick Clarke-Palmore House in Henrico County, Virginia, has a lower level built in 1819 described as being American bond of 3 to 5 stretcher courses between each header course, and an upper level built in 1855 with American bond of 6 to 7 stretcher courses between each header course. and [http://www.dhr.virginia.gov/registers/Counties/Henrico/Clarke-Palmore_photo.htm Accompanying four photos at Virginia Historic Landmarks Commission, undated] Garden wall bonds English garden wall bond - an english bond where either three or five courses of stretchers are laid to every course of headers. Flemish garden Wall Bond - a flemish bond where either three or five stretchers are laid between the headers. Water Bond - a nine inch wall bond where both skins are built in stretcher bond, but the bed joints in are staggered so as not to align. This bond is often specified by local councils in the North of England for manholes. Rat-trap bond Rat-trap bond, also known as Chinese bond, is a type of garden wall bond similar to Flemish, but consisting of rowlocks and shiners instead of headers and stretchers (the stretchers and headers are laid on their sides, with the base of the stretcher facing outwards). This gives a wall with an internal cavity bridged by the headers, hence the name. The main advantage of this bond is economy in use of bricks, giving a wall of one brick thickness with fewer bricks than a solid bond. Rat-trap bond was in common usage in England for building houses of fewer than 3 stories up to the turn of the 20th century and is today still used in India as an economical bond, as well for the insulation properties offered by the air cavity. Also, many brick walls surrounding kitchen gardens were designed with cavities so hot air could circulate in the winter, warming fruit trees or other produce spread against the walls, causing them to bloom earlier and forcing early fruit production. See also *International Union of Bricklayers and Allied Craftworkers *Construction *Masonry *Tuckpointing References External links * DIYinfo.org's Brick Laying Wiki - Practical information on laying bricks * Brick patterns for wall and pavement * National Concrete Masonry Association * Details on turning corners and adjoining walls by the use of bats and queen closers * Brickwork Bonds and net quantities per m³ Diagrams of most types of bond * Good photos and discussion of English brickwork and its history Category:Construction Category:Bricks